8.3.3 User-Programmable Reset Time Delay for TLV841C only

The reset time delay can be set to a typical value of 40 µs by leaving the CT pin floating, or a maximum value of

by connecting a capacitor no larger than 10 µF between the CT pin and GND.

is given by Equation 3.

(3)

(4)

(5)

(6)

The recommended maximum delay capacitor for the TLV841C is limited to 10 μF as this ensures enough time

for the capacitor to fully discharge when a voltage fault occurs. Also, having a too large of a capacitor value

can cause very slow charge up (rise times) and system noise can cause the the internal circuit to trip earlier or

later near the threshold. This leads to variation in time delay where it can make the delay accuracy worse in the

presence of system noise.

When a voltage fault occurs, the previously charged up capacitor discharges and if the monitored voltage

returns from the fault condition before the delay capacitor discharges completely, the delay will be shorter than

expected. The capacitor will begin charging from a voltage above zero and resulting in shorter than expected

time delay. A larger delay capacitor can be used so long as the capacitor has enough time to fully discharge

during the duration of the voltage fault. The amount of time required to discharge the delay capacitor relative

to the reset delay rises as VDD fault undervoltage increases as shown in Figure 8-5. From the graph below,

greater than 10% of the programmed reset time delay.

VDD Fault Underoltage (V)

0.6

0.8

1

1.2

1.4

1.6

1.8

2

5

10

15

20

25

30

35

40

45

50

55

CTR_

25°C

TLV841

SLVSFO5C – APRIL 2020 – REVISED JULY 2021

www.ti.com

16

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